Synthesis, molecular modeling and biological evaluation of chalcone thiosemicarbazide derivatives as novel anticancer agents

Synthesis of novel carbazole hydrazine-carbothioamide scaffold as potent antioxidant, anticancer and antimicrobial agents

BACKGROUND

Carbazole-based molecules containing thiosemicarbazide functional groups are recognized for their diverse biological activities, particularly in enhancing therapeutic anticancer effects through inhibiting crucial pathways. These derivatives also exhibit noteworthy antioxidant properties.

OBJECTIVES

This study aims to synthesize, characterize, and evaluate the antioxidant and anticancer activities of 18 novel carbazole derivatives.

METHODS

The radical scavenging capabilities of the compounds were assessed using the 2,2-diphenyl-1-picrylhydrazyl assay. Antiproliferative activities were evaluated on MCF-7 cancer cell lines through viability assays. Additionally, the modulation of the PI3K/Akt/mTOR pathway, apoptosis/necrosis induction, and cell cycle analysis were conducted for the most promising anticancer agents.

RESULTS

nine compounds showed potent antioxidant activities with IC50 values lower than the positive control acarbose, with compounds 4 h and 4y exhibiting the highest potency (IC50 values of 0.73 and 0.38 µM, respectively). Furthermore, compounds 4o and 4r displayed significant anticancer effects, with IC50 values of 2.02 and 4.99 µM, respectively. Compound 4o, in particular, exhibited promising activity by targeting the PI3K/Akt/mTOR signaling pathway, inhibiting tumor survival, inducing apoptosis, and causing cell cycle arrest in MCF-7 cell lines. Furthermore, compound 4o was showed significant antimicrobial activities against S. aureus and E. coli, and antifungal effect against C. albicans. Its potential to overcome drug resistance through this pathway inhibition highlights its promise as an anticancer agent. Molecular docking simulations supported these findings, revealing favorable binding profiles and interactions within the active sites of the enzymes PI3K, AKT1, and mTOR. Moreover, assessing the druggability of the newly synthesized thiosemicarbazide derivatives demonstrated optimal physicochemical properties, further endorsing their potential as drug candidates.

Newly synthesized derivatives with a thiosemicarbazide group reduce the viability of cancer cell lines. Acute toxicity assessment in Zebrafish (Danio rerio) early life stages

Due to the variability and ability of tumor to mutate, as well as the heterogeneity of tumor tissue, such drugs are sought that would act selectively and multidirectionally on the cancer cell. Therefore, two newly synthesized semicarbazide structured substances were evaluated for anticancer properties in our study: 1a and 1b. In order to evaluate the cytotoxicity and selectivity of the tested compounds, MTT and Neutral Red uptake assay on cell lines (HEK293, LN229, 769-P, HepG2 and NCI-H1563) and cell cycle analysis were performed. Acute toxicity and cardiotoxicity were also evaluated in the zebrafish model. The tested compounds (1a, 1b) showed cytotoxic activity, with the greatest selectivity noted against the glioblastoma multiforme cell line (LN229). However, compound 1b showed stronger selective activity than 1a. Both of compounds were shown to significantly affect the M phase of the cell cycle. Whereas, the conducted toxicological examination of newly synthesized thiosemicarbazide derivates showed, that direct exposition of Danio rerio embryos to compound 1a, but not 1b, causes a concentration-dependent increase in developmental malformations, indicating possible teratogenic effects.

Ligand and structure based hierarchical virtual screening cascade for finding novel epidermal growth factor receptor inhibitors

The epidermal growth factor receptor (EGFR) tyrosine kinase plays an important role in tumor formation and growth by mediating cell growth and other physiological processes. Therefore, EGFR is a promising target for the treatment of cancer. In this work, we combined ligand-based and structure-based virtual screening methods to identify novel EGFR inhibitors from a library of more than 103 thousand compounds. We first obtained hundreds of compounds with similar physiochemical properties through 3D molecular shape and electrostatic similarity screening with potent inhibitors AEE788 and Afatinib as queries. Next, we identified compounds with strong binding affinities to the EGFR pocket through molecular docking, which makes good use of the structure information of the receptor. After molecular scaffold analysis, our bioassay confirmed 13 compounds with EGFR inhibitory activity and three compounds had IC50 values below 1000 nM. In addition, we collected 5371 EGFR inhibitors from online databases, and clustered them into 7 groups by K-means method using their ECFP4 fingerprints as input. Each cluster had typical molecular fragments and corresponding activity characteristics, which could guide the design of EGFR inhibitors, and we concluded that the fragments from some of the hits are indicated in the highly active scaffolds.

Design, In Silico Molecular Docking, and ADMET Prediction of Amide Derivatives of Chalcone Nucleus as EGFR Inhibitors for the Treatment of Cancer

BACKGROUND

Cancer is a devastating disease. Many studies have shown that the primary causes of the aggressive and resistant types of cancer are the overexpression of receptors and growth factors, activation of oncogenes, and the inactivation of tumour suppressor genes. One such receptor is the epidermal growth factor receptor (EGFR), which is used as a drug target for the treatment of cancer.

OBJECTIVE

This study aimed to develop the new chemical entities of amide derivatives of chalcone as EGFR inhibitors using structure-activity relationship (SAR) studies, molecular docking, and ADMET (absorption, distribution, metabolism, excretion, and toxicity) studies.

METHOD

New chemical entities (NCE) were designed based on literature findings. The Schrodinger 13.4 software was used for the molecular docking study. While Quickprop and Pro Tox-II online tools were used for ADME and toxicity prediction, respectively. .

RESULT

In this work, all compounds were subjected to an in-silico ADMET analysis. After pharmacokinetic and toxicity profile predictions, the molecules were further analysed by molecular docking. As a result of molecular docking, molecules AC9 and AC19 showed comparable docking scores compared to standard Afatinib.

CONCLUSION

Molecules AC9 and AC19 showed good docking scores and a promising ADMET profile. In the future, these derivatives can be further evaluated for wet lab studies and determination of their biological activity.

Investigation of Gold Nanoparticle Naproxen-Derived Conjugations in Ovarian Cancer

Ovarian cancer, which is one of the most diagnosed cancer types among women, maintains its significance as a global health problem. Several drug candidates have been investigated for the potential treatment of ovarian cancer. Nonsteroidal anti-inflammatory drugs (NSAIDs) demonstrated anti-cancer activity through the inhibition of cyclooxygenase 2 (COX-2) and by inhibiting COX-2-dependent prostaglandin (PG) production. Naproxen is one of the most used NSAIDs and Naproxen-derived compounds (NDCs) may show potential treatment effects on cancer as chemotherapeutic drugs. Although there are successful drug development studies, the lack of solubility of these drug candidates in aqueous media results in limited bioavailability and high variability of patient responses during treatment. Low aqueous solubility is one of the main problems in the pharmaceutical industry in terms of drug development. Nanotechnology-based strategies provide solutions to hydrophobic drug limitations by increasing dispersion and improving internalization. In this study, two different NDCs (NDC-1 and NDC-2) bearing a thiosemicarbazide/1,2,4-triazole moiety were synthesized and tested for chemotherapeutic effects on ovarian cancer cells, which have a high COX-2 expression. To overcome the limited dispersion of these hydrophobic drugs, the drug molecules were conjugated to the surface of 13 nm AuNPs. Conjugation of drugs to AuNPs increased the distribution of drugs in aqueous media, and NDC@AuNP conjugates exhibited excellent colloidal stability for up to 8 weeks. The proposed system demonstrated an increased chemotherapeutic effect than the free drug counterparts with at least 5 times lower IC50 values. NDC@AuNP nanosystems induced higher apoptosis rates, which established a simple and novel way to investigate activity of prospective drugs in drug discovery research.

Evaluation of azothioformamides and their copper(I) and silver(I) complexes for biological activity

Redox-active azothioformamides (ATFs) contain an NNCS 1,3-heterodiene motif typically found in other molecular subclasses that exhibit a wide range of cytotoxic and anti-neoplastic effects, either alone or as chelation complexes with various metals. For this study, a small library of ATF compounds was synthesized and tested across a range of microbes, fungi, and cancer cell lines for biological activity, both alone and as metal chelates of copper(I) and silver(I) salts. Alone, the ATF compounds exhibited little antimicrobial activity, but all inhibited the cell growth of A549 lung carcinoma cells (IC50 values of 1-6 μM). As copper(I) and silver(I) coordination complexes, several of the ATFs showed antimicrobial activity against gram positive Staphylococcus aureus and Bacillus subtilis cells (IC50 ∼ 5-20 μM) and the fungi Candida albicans (IC50 ∼ 8-12 μM); as well as cytotoxicity against both lung carcinoma A549 cells and lymphoblastic leukemia K562 cells.

Novel Zn(II)-complex with hybrid chalcone-thiosemicarbazone ligand: Synthesis, characterization, and inhibitory effect on HTLV-1-infected MT-2 leukemia cells

Chalcone and thiosemicarbazone have attracted attention due to their easy synthetic procedure and high success in the development of antiviral and antitumor, however, there are few biological data on the evaluation of chalcone-thiosemicarbazone hybrids and their complexation with metal ions. In this sense, the present work reports the synthesis and characterization of the hybrid (Z)-2-((E)-3-(4-chlorophenyl)-1-phenylallylidene)hydrazine-1-carbothioamide (CTCl) and its Zn(II)-complex (CTCl-Zn). The compounds were cell-based evaluated in terms of cytotoxicity against human T-cell lymphotropic virus type 1 (HTLV-1) infected leukemia cells (MT-2) and the experimental data were correlated with molecular docking calculations. The ligand and Zn(II)-complex were easily synthesized with a good yield - 57% and 79%, respectively. The dynamic of E/Z isomers with respect to the imine bond configuration of CTCl was evidenced by 1H NMR experiments in DMSO‑d6, while the X-ray diffraction of CTCl-Zn showed that Zn(II) ion is tetracoordinated to two ligands in a bidentate mode and the metal ion lies on an intermediate geometry between the see-saw and trigonal pyramid. The ligand and complex exhibited low toxicity and the Zn(II)-complex is more cytotoxic than the ligand, with the corresponding IC50 value of 30.01 and 47.06 μM. Both compounds had a pro-apoptotic effect without the release of reactive oxygen species (ROS) and they can interact with DNA via minor grooves driven by van der Waals forces.

Structural and functional insight into thiazolidinone derivatives as novel candidates for anticancer drug design: in vitro biological and in-silico strategies

The compounds 2a-2h containing a thiazolidinone pharmacophore were synthesized via hetrerocylization of thiosemicarbazones with dimethyl acetylenedicarboxylate. The hybrid molecules were evaluated for anticancer activity against the human cell lines MCF-7, T47D (human breast adenocarcinoma) and HeLa (cervical cancer). Compounds 2c showed effective cytotoxicity on MCF-7 and HeLa (GI₅₀ 6.40 ± 0.10 μM/mL and GI₅₀10.30 ± 1.09 μM/mL), and compound 2d also showed effective cytotoxicity against MCF-7 and HeLa cell lines i.e., (GI₅₀ 16.60 ± 0.21 μM/mL and GI₅₀ 15.02 ± 0.14 μM/mL). These findings were comparable to cisplatin (azane;dichloroplatinum) the standard drug (GI₅₀ 13.20 ± μM/mL and 15.10 μM/mL respectively) and consequently nominated for determination of the mode of cell death. The results revealed the cytotoxic effects of 2c and 2d by induction of apoptosis in MCF-7 and HeLa cell lines. Moreover the results were further supported by the Molecular Docking which predicts the binding interactions of the best anticancer ligands with Ribonucleotide reductase (RNR), which is essential enzyme required for de-novo synthesis of DNA precursors. Molecular dynamic simulations were also performed to determine the stability of protein-ligand complex under different simulated conditions. In addition, the computational studies including DFTs, ADMET properties suggested these compounds can act as lead molecules, for the synthesis of novel drug candidates for the treatment of specific cancer and its associated malignancies.

Design, Synthesis, Inhibitory Activity, and Molecular Modeling of Novel Pyrazole-Furan/Thiophene Carboxamide Hybrids as Potential Fungicides Targeting Succinate Dehydrogenase

To discover new fungicides targeting succinate dehydrogenase (SDH), 36 new furan/thiophene carboxamides containing 4,5-dihydropyrazole rings were designed, synthesized, and characterized. The crystal structure of compound 5l was determined with the X-ray diffraction (XRD) of single crystals. The antifungal activity of these compounds was studied against Botrytis cinerea, Pyricularia oryzae, Erysiphe graminis, Physalospora piricola, and Penicillium digitatum. Bioassay results were that most compounds had obvious inhibitory activity at 20 μg/mL. Compounds 5j, 5k, and 5l possessed outstanding inhibitory activity against B. cinerea. Their EC₅₀ values were 0.540, 0.676, and 0.392 μg/mL, respectively. They owned better effects than fluxapyroxad (EC₅₀ = 0.791 μg/mL). In the meantime, the inhibitory activity of 16 compounds was evaluated against SDH. It turned out that these compounds displayed excellent activity. The IC₅₀ values of compounds 5j, 5k, and 5l reached 0.738, 0.873, and 0.506 μg/mL, respectively, whereas the IC₅₀ value of fluxapyroxad was 1.031 μg/mL. The results of molecular dynamics (MD) simulation showed that compound 5l possessed a stronger affinity to SDH than fluxapyroxad.

Evaluation of developmental toxicity in zebrafish embryos and antiproliferative potential against human tumor cell lines of new derivatives containing 4-nitrophenyl group

The aim of the studies was to evaluate the antiproliferative potential against human tumor cell lines of newly synthetized derivatives containing 4-nitrophenyl group, as well as its impact on developmental toxicity in zebrafish model. We selected 1-(4-nitrobenzoyl)-4-ethylsemicarbazide (APS-1) and 1-[(4-nitrophenyl)acetyl]-4-hexyl-thiosemicarbazide (APS-18) for research. The antiproliferative properties of semicarbazide derivatives were assessed against human cancer cell lines derived from hepatocellular adenocarcinoma (HepG2), renal cell carcinoma (769-P), non-small cell lung cancer (NCI-H1563) and glioblastoma multiforme (LN229) in comparison to the physiological human embryonic kidney (HEK-293) cell line. The influence of the tested substances on the cell cycle and apoptosis was also evaluated. Fish embryo acute toxicity test (FET) was performed based on OECD Guidelines (Test No. 236), and was carried out for the first 5 days post fertilization. The following concentrations of APS-1 and APS-18 were tested: 125-2000 μM and 0.125-1000 μM, respectively. The presented studies on the antiproliferative properties of the new semicarbazide derivatives showed that the compounds APS-1 and APS-18 reduce the viability of human tumor lines. Particularly noteworthy is the strong and selective antiproliferative activity of APS-18 against all neoplastic cell lines, in particular against glioblastoma. Against this tumor line, the compound APS-1 showed an effective inhibitory effect. In the FET we noted that the direct exposure of zebrafish embryos to APS-1 and APS-18 in used range of concentration did not cause morphological abnormalities, including cardiotoxicity. On basis of obtained outcomes it could be concluded that APS-1 and APS-18 may constitute models for further research, design and synthesis of new, safer drugs with more favorable anticancer properties.

Synthesis and Anticancer Activities of Novel Bis-chalcones Incorporating the 1,3-diphenyl-1H-pyrazole Moiety: In Silico and In Vitro Studies

Abstract:

A new series of bis-chalcones 5-10 has been prepared by the condensation reaction of one equivalent of bis(acetophenones) 3a-f with two equivalents of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde 4. The newly prepared compounds 5-10 have been fully characterized and evaluated as in vitro anticancer agents against a panel of human cancer cell lines A431, A549, PC3, and a normal human skin fibroblast BJ1.

Aims:

The current work is designed to explore the anti-cancer activity of novel bis-chalcones incorporating a 1,3-diphenyl-1H-pyrazole moiety.

Background:

Chalcones represent one of the most important organic compounds that have been attracting the interest of many researchers in drug discovery.

Objective:

The present study was carried out to explore anti-cancer activity of novel bis-chalcones incorporating a 1,3-diphenyl-1H-pyrazole moiety as in vitro and in silico studies.

Materials and Methods:

We used the condensation reaction to prepare bis-chalcones incorporating 1,3- diphenyl-1H-pyrazole moiety. The MTT Assay, Anti-cancer activity, Gene expression, DNA Fragmentation, DNA Damage, and Molecular docking were investigated.

Results:

Compounds 5 and 9 were found to be the most promising compounds in the prepared series with IC50 (50.3 and 50.1 μg/ml, respectively) against epidermoid cancer cell line A431 compared to doxorubicin as a reference drug.

Conclusion:

All of these results showed that chalcones 5 and 9 have promising anti-cancer properties without cytotoxic effect, which could make them a promising active component for further studies.

Synthesis, molecular modelling and antibacterial activity of 4-aryl-thiosemicarbazides

N-Substituted phenyl/cyclohexyl-2-(pyridine-4-carbonyl) hydrazine-1-carbothioamides (2a–r) were synthesized, characterized by spectral and analytical data. The compounds were evaluated for antibacterial activity by the disc diffusion method. Most of the compounds showed activity against Gram-positive bacteria. Compound 2h with 4-Sulfapyrimidine phenyl substitution was found to be the most promising candidate, active against Gram-positive and methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) of (2–7 μg/mL). From the docking study, we predicted that compounds (2r, 2g, 2h, 2o, 2p and 2e) possess better antibacterial activity by having a good binding affinity with target protein and they could be used as potential drugs as antimicrobials. Amongst all the docked compounds, the compound 2h presented near binding affinity & interaction docking score with DNA gyrase enzymes with reference to ciprofloxacin.

Synthesis, Anticancer Assessment, and Molecular Docking of Novel Chalcone-Thienopyrimidine Derivatives in HepG2 and MCF-7 Cell Lines

Heterocycles containing thienopyrimidine moieties have attracted attention due to their interesting biological and pharmacological activities. In this research article, we reported the synthesis of a series of new hybrid molecules through merging the structural features of chalcones and pyridothienopyrimidinones. Our results indicated that the synthesis of chalcone-thienopyrimidine derivatives from the corresponding thienopyrimidine and chalcones proceeded in a relatively short reaction time with good yields and high purity. Most of these novel compounds exhibited moderate to robust cytotoxicity against HepG2 and MCF-7 cancer cells similar to that of 5-fluorouracil (5-FU). The results indicated that IC₅₀ of the two compounds (3b and 3g) showed more potent anticancer activities against HepG2 and MCF-7 than 5-FU. An MTT assay and flow cytometry showed that only 3b and 3g had anticancer activity and antiproliferative activities at the G1 phase against MCF-7 cells, while six compounds (3a-e and 3g) had cytotoxicity and cell cycle arrest at different phases against HepG2 cells. Their cytotoxicity was achieved through downregulation of Bcl-2 and upregulation of Bax, caspase-3, and caspase-9. Although all tested compounds increased oxidative stress via increment of MDA levels and decrement of glutathione reductase (GR) activities compared to control, the 3a, 3b, and 3g in HepG2 and 3b and 3g in MCF-7 achieved the target results. Moreover, there was a positive correlation between cytotoxic efficacy of the compound and apoptosis in both HepG2 (R ² = 0.531; P = 0.001) and MCF-7 (R ² = 0.219; P = 0.349) cell lines. The results of molecular docking analysis of 3a-g into the binding groove of Bcl-2 revealed relatively moderate binding free energies compared to the selective Bcl-2 inhibitor, DRO. Like venetoclax, compounds 3a-g showed 2 violations from Lipinski's rule. However, the results of the ADME study also revealed higher drug-likeness scores for compounds 3a-g than for venetoclax. In conclusion, the tested newly synthesized chalcone-pyridothienopyrimidinone derivatives showed promising antiproliferative and apoptotic effects. Mechanistically, the compounds increased ROS production with concomitant cell cycle arrest and apoptosis. Therefore, regulation of the cell cycle and apoptosis are possible targets for anticancer therapy. The tested compounds could be potent anticancer agents to be tested in future clinical trials after extensive pharmacodynamic, pharmacokinetic, and toxicity profile investigations.

Design, synthesis, and in vitro and in vivo anticancer activity studies of new (S)-Naproxen thiosemicarbazide/1,2,4-triazole derivatives

This study includes the synthesis of new Naproxen derivatives and in vitro–in vivo molecular mechanistic studies.

A Review: Discovering 1,3,4-oxadiazole and chalcone nucleus for cytotoxicity/EGFR inhibitory anticancer activity

INTRODUCTION

Cancer is reported to be one of the most life-threatening diseases. Major limitations of currently used anticancer agents are drug resistance, very small therapeutic index, and severe, multiple side effects.

OBJECTIVE

The current scenario necessitates developing new anticancer agents, acting on novel targets for effectively controlling cancer. The epidermal growth factor receptor is one such target, which is being explored for 1,3,4-oxadiazole and chalcone nuclei.

METHOD

Findings of different researchers working on these scaffolds have been reviewed and analyzed, and the outcomes were summarized. This review focuses on Structure-Activity Relationship studies (SARs) and computational studies of various 1,3,4-oxadiazole and chalcone hybrids/derivatives reported as cytotoxic/EGFR-TK inhibitory anticancer activity.

RESULT AND CONCLUSION

1,3,4-oxadiazole and chalcone hybrids/derivatives with varied substitutions are found to be effective pharmacophores in obtaining potent anticancer activity. Having done a thorough literature survey, we conclude that this review will surely provide firm and better insights to the researchers to design and develop potent hybrids/derivatives that inhibit EGFR.

Design, synthesis and inhibitory activity of novel 2, 3-dihydroquinolin-4(1H)-one derivatives as potential succinate dehydrogenase inhibitors

Thirty-three new 2, 3-dihydroquinolin-4(1H)-one analogues were designed, synthesized and characterized by IR, ¹H NMR, ¹³C NMR and HRMS. The crystal structures of compounds 2g and 4l were characterized by single crystal X-ray diffraction. Their antifungal activities were determined against five plant pathogenic fungi namely Rhizoctonia solani, Fusarum graminearum, Helminthosporium maydis, Sclerotinia sclerotiorum and Botrytis cinerea. The results indicated that most of them revealed significant antifungal activity at 20 mg/L. Compound 4e showed the strongest antifungal activity against Botrytis cinerea and had better effects than the commercial fungicide fluopyram. Meanwhile, the active compounds were evaluated for their inhibitory activities against succinate dehydrogenase (SDH). The results displayed that they exhibited excellent activity. Compound 4e had better inhibitory activity than fluopyram. The molecular modeling results demonstrated that compound 4e could strongly bind to and interact with the binding sites of SDH. The inhibitory activity of 2, 3-dihydroquinolin-4(1H)-one derivatives against SDH has been reported for the first time.

Synthesis, characterization, and anti-cancer activity of new chalcone derivatives containing naphthalene and fluorine moieties

In recent years, chalcones and their derivatives have become the focus of global scientists due to increasing evidence reported towards their potency in antitumor and anti-cancer. Here, the chalcones designed and synthesized in our present study were derived from the derivatives of naphthaldehyde and acetophenone. Both these precursors have been reported in demonstrating a certain degree of anticancer property. Also, the substituents on these precursors such as hydroxyl, methoxy, prenyl, and chloro were shown able to enhance the anticancer efficiency. Hence, it is the interest of the current study to investigate the anticancer potential of the hybrid molecules (chalcones) consisting of these precursors with different alkoxy substituents and with or without the fluorine moiety. Two series of chalcone derivatives were designed, synthesized, and characterized using the elemental analysis, IR, 1 H and 13 C NMR spectroscopy, subsequently evaluated for their anti-cancer activity. Interestingly, the results showed that the fluorinated chalcones 11-15 exhibited stronger cytotoxic activity towards the breast cancer cell lines (4T1) compared to non-fluorinated chalcone derivatives. Remarkably, the selectivity index obtained for these fluorinated chalcones derivatives against the breast cancer 4T1 cell line was higher than those exhibited by cisplatin, which is one of the most frequently deployed chemotherapy agents in current medical practice. These findings could provide an insight towards the potential of fluorinated chalcones being developed as an anti-cancer agent with moderate activity towards breast cancer cell and low inhibition of fibroblast cell at a concentration of 100 μM.

Design, synthesis and insecticidal activity of novel semicarbazones and thiosemicarbazones derived from chalcone

Thirty semicarbazone and thiosemicarbazone derivatives (2a-w and 4a-g) from chalcones containing furan and thiophene ring were designed and synthesized. They were characterized by IR, ¹H NMR, ¹³C NMR and HRMS. The crystal structure of compound 2r was characterized by single crystal X-ray diffraction. It crystallizes in the monoclinic system with space group P2₁/c. The insecticidal activity of the synthesized compounds was screened against Leucania separata and Pieris rapae using beta-cypermethrin as the comparative standard. The results displayed that most of them had remarkable insecticidal activity. Among them, compounds 2e-g showed better activity than beta-cypermethrin against L. separata and P. rapae. Compound 2p also possessed a better activity than beta-cypermethrin against P. rapae. The insecticidal activities of these compounds have been reported for the first time.

A Review of the Structure-Activity Relationship of Natural and Synthetic Antimetastatic Compounds

There are innumerable anticancer compounds derived from either natural or synthetic origins. Many of these compounds have been further developed through structural modifications to not only inhibit cancer cell growth but also to exert an antimetastatic effect. This is achieved by attaching different substituents to generate different structure—activity relationships. This review highlights the effectiveness of different functional groups known to have antimigration and antiproliferation activities, such as fluoro, methoxy, methyl, amino, hydroxy, nitro, bromo, chloro, methylamino, ethoxy, carbonyl, iodo, and trifluoromethyl groups. Additionally, the positioning of these functional groups plays an important role in their anticancer activities, which was evident in one of our studies comparing analogues of a natural compound. Thus, this review suggests future recommendations for the design and development of improved anticancer drugs with higher efficacy.

Investigation on Quantitative Structure-Activity Relationships of 1,3,4-Oxadiazole Derivatives as Potential Telomerase Inhibitors

BACKGROUND

Telomerase, a reverse transcriptase, maintains telomere and chromosomes integrity of dividing cells, while it is inactivated in most somatic cells. In tumor cells, telomerase is highly activated, and works in order to maintain the length of telomeres causing immortality, hence it could be considered as a potential marker to tumorigenesis.A series of 1,3,4-oxadiazole derivatives showed significant broad-spectrum anticancer activity against different cell lines, and demonstrated telomerase inhibition.

METHODS

This series of 24 N-benzylidene-2-((5-(pyridine-4-yl)-1,3,4-oxadiazol-2yl)thio)acetohydrazide derivatives as telomerase inhibitors has been considered to carry out QSAR studies. The endpoint to build QSAR models is determined by the IC50 values for telomerase inhibition, i.e., the concentration (μM) of inhibitor that produces 50% inhibition. These values were converted to pIC50 (- log IC50) values. We used the most common and transparent method, where models are described by clearly expressed mathematical equations: Multiple Linear Regression (MLR) by Ordinary Least Squares (OLS).

RESULTS

Validated models with high correlation coefficients were developed. The Multiple Linear Regression (MLR) models, by Ordinary Least Squares (OLS), showed good robustness and predictive capability, according to the Multi-Criteria Decision Making (MCDM = 0.8352), a technique that simultaneously enhances the performances of a certain number of criteria. The descriptors selected for the models, such as electrotopological state (E-state) descriptors, and extended topochemical atom (ETA) descriptors, showed the relevant chemical information contributing to the activity of these compounds.

CONCLUSION

The results obtained in this study make sure about the identification of potential hits as prospective telomerase inhibitors.

Evaluation of Novel Chalcone-Thiosemicarbazones Derivatives as Potential Anti-Leishmania amazonensis Agents and Its HSA Binding Studies

A series of seven chalcone-thiosemicarbazones (5a-5g) were synthesized and evaluated as potential new drugs (anti-leishmanial effect). Although four of the chalcone-thiosemicarbazones are already known, none of them or any compound in this class has been previously investigated for their effects on parasites of the Leishmania genus. The compounds were prepared in satisfactory yields (40-75%) and these compounds were evaluated against promastigotes, axenic amastigotes and intracellular amastigotes of L. amazonensis after 48 h of culture. The half maximal inhibitory concentration (IC₅₀) values of the intracellular amastigotes were determined to be in the range of 3.40 to 5.95 µM for all compounds assayed. The selectivity index showed value of 15.05 for 5a, whereas pentamidine (reference drug) was more toxic in our model (SI = 2.32). Furthermore, to understand the preliminary relationship between the anti-leishmanial activity of the chalcone-thiosemicarbazones, their electronic (σ), steric (MR) and lipophilicity (π) properties were correlated, and the results indicated that moieties with electronic withdrawing effects increase the anti-leishmanial activity. The preliminary pharmacokinetic evaluation of one of the most active compound (5e) was studied via interaction to human serum albumin (HSA) using multiple spectroscopic techniques combined with molecular docking. The results of antiparasitic effects against L. amazonensis revealed the chalcone-thiosemicarbazone class to be novel prototypes for drug development against leishmaniasis.

Synthesis and characterisation of novel 4,6-dimethoxyindole-7- and -2-thiosemicarbazone derivatives: Biological evaluation as antioxidant and anticholinesterase candidates

Two sets of novel indole-based thiosemicarbazone systems 8a–d and 9a–d are prepared by the Schiff base condensation reaction of indole carbaldehydes 4 and 6 with a range of thiosemicarbazides 7a–d in high yields and purity. The antioxidant properties of the synthesised compounds 8a–d and 9a–d are determined by employing three different assays, namely 2,2-diphenyl-1-picrylhydrazyl hydrate–free radical scavenging, ABTS [2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] cationic radical decolarization and cupric ion reducing antioxidant capacity. The anticholinesterase properties of the products are investigated by acetylcholinesterase and butyrylcholinesterase enzyme inhibition assays. The methyl-substituted compounds 8b and 9b display the highest inhibition for the ABTS assay and absorbance values for the cupric ion reducing antioxidant capacity assay, while compound 9c shows the best activity for 2,2-diphenyl-1-picrylhydrazyl hydrate assay. Moderate inhibition of acetylcholinesterase and butyrylcholinesterase is determined in the case of compound 8b.

Studies on Isoniazid Derivatives through a Medicinal Chemistry Approach for the Identification of New Inhibitors of Urease and Inflammatory Markers

A library of thiosemicarbazide derivatives of isoniazid 3-27, was synthesized and evaluated for their anti-inflammatory and urease inhibition activities, by using in vitro bioassays. Among these compounds 9, 10, 12, 21, and 26 were identified as new derivatives. Prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs) and infections caused by Helicobacter pylori (ureolytic bacteria), are the two most significant causes of gastric and peptic ulcers. We focused on the identification of the dual inhibitors of inflammation and urease enzyme. Compound 23 was identified as the best dual inhibitor of inflammation (ROS; IC50 = 12.3 µg/mL), and urease enzyme inhibition activity (IC50 = 22.4 µM). Many of these compounds showed comparable activities to the standard anti-inflammatory drug (ibuprofen, IC50 = 11.2 µg/mL) and urease inhibitor (thiourea/acetohydraoxamic acid, IC50 = 21.1/20.3 µM). Compound 12 was found to be the most potent urease inhibitor (IC50 = 12.3 µM) and good inhibitor of inflammation (IC50 = 27.7 µg/mL). Compounds 19, 11, 13, 9, 17, 10, and 16, were also found to be potent inhibitors of urease. Cytotoxicity was also evaluated and all the compounds were found to be non-cytotoxic, except compound 18 and the parent drug isoniazid (IC50 = 29.5 and 28.5 µM, respectively).

ACI/EG eutectic mixture mediated synthesis, characterization and in vitro osteoblast differentiation assessment of spiropyrrolo[1,2-b]isoquinoline analogues

An eco-friendly acetylcholine iodide-ethylene glycol (ACI/EG) deep eutectic mixture mediated green protocol has been developed for the synthesis of hitherto unexplored multi-functionalized linear tricyclic spiropyrrolo[1,2-b]isoquinoline analogues. The effects of the synthesized compounds on the osteoblast differentiation of hBMSC-TERT cell lines were investigated and promising results were observed with significant IC50 values. In addition, molecular modeling simulations were also performed with the 3D structure of BMP-2 to reveal binding interactions and orientations of highly potent spiropyrrolo[1,2-b]isoquinoline analogues.

Copper complex derived from S-benzyldithiocarbazate and 3-acetylcoumarin induced apoptosis in breast cancer cell

Copper complexes have been widely studied for the anti-tumour application as cancer cells are reported to take up greater amounts of copper than normal cells. Preliminary study revealed that the newly synthesised copper complex [Cu(SBCM)₂] displayed marked anti-proliferative towards triple-negative MDA-MB-231 breast cancer cells. Therefore, Cu(SBCM)₂ has great potential to be developed as an agent for the management of breast cancer. The present study was carried out to investigate the mode of cell death induced by Cu(SBCM)₂ towards MDA-MB-231 breast cancer cells. The inhibitory and morphological changes of MDA-MB-231 cells treated with Cu(SBCM)₂ was determined by using MTT assay and inverted light microscope, respectively. The safety profile of Cu(SBCM)₂ was also evaluated towards human dermal fibroblast (HDF) normal cells. Confirmation of apoptosis and cell cycle arrest were determined by flow cytometry analysis. The expression of p53, Bax, Bcl-2 and MMP2 protein were detected with western blot analysis. Cu(SBCM)₂ significantly inhibited the growth of MDA-MB-231 cells in a dose-dependent manner with GI₅₀ 18.7 ± 3.06 µM. Indeed, Cu(SBCM)₂ was less toxic towards HDF normal cells with GI₅₀ 31.8 ± 4.0 µM. Morphological study revealed that Cu(SBCM)₂-treated MDA-MB-231 cells experienced cellular shrinkage, membrane blebbing, chromatin condensation and formation of apoptotic bodies, suggesting that Cu(SBCM)₂ induced apoptosis in the cells, which was confirmed by Annexin-V/PI flow cytometry analysis. It was also found that Cu(SBCM)₂ induced G₂/M phase cell cycle arrest towards MDA-MB-231 cells. The induction of apoptosis and cell cycle arrest in the present study is possibly due to the down-regulation of the mutant p53 and MMP2 protein. In conclusion, Cu(SBCM)₂ can be developed as a targeted therapy for the treatment of triple-negative breast cancer.

Chalcone: A Privileged Structure in Medicinal Chemistry

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.